Latest Situation Updates
The latest version (Vol 34, July 2014, No. 2) of the Mehtaensis newsletter (a 6 monthly newsletter named after Prof. K.C. Mehta) has just been published by the DWR, Regional Station, Flowerdale, Shimla. Compiled by Dr. S.C. Bhardwaj, O.P. Gangwar, P. Prasad and Hanif Khan with technical assistance from: S.B. Singh, Subodh Kumar (Mehtaensis July 2014 Vol.34No.2). Mehtaensis contains a detailed summary of all the rust activities and race analysis results from India and neighbouring South Asian countries during the 2013/14 season. Reported highlights are summarized as follows:
There was no major outbreak of wheat rusts in India during 2013-14. However, sporadic incidence of yellow rust of wheat was observed at some locations in Northern India. Stem (Black) rust of wheat was reported on indigenous experimental wheat material planted in Uttarakhand and barley material in Karnataka. During the year 1625 samples of different rusts of wheat and barley were received/collected for pathotype analyses. Analyses of more than 1209 samples revealed that the wheat rust population analyzed is avirulent to Yr5, Yr10, Yr11, Yr12, Yr13, Yr14, Yr15, Yr24, Yr26, YrSp and YrSk (yellow/stripe rust); to Sr26, Sr27, Sr31, Sr32, Sr35, Sr39, Sr40, Sr43, SrTt3 and SrTmp (black/stem rust); to Lr24, Lr25, Lr29, Lr32, Lr39, Lr42 and Lr45 (brown/leaf rust). Predominant pathotypes were; (i) yellow/stripe rust: 46S119 (74% of samples) and 78S84 (18.5% of samples); (ii) brown/leaf rust: 77-5 (121R63-1=THTTM) predominant, followed by 104-2 (21R55=PHTTL); (iii) black/stem rust: pathotype 11 (79G31=RRTSF) was predominant followed by pathotype 40A (62G29=PTHSC). One new pathotype each of the three wheat rusts were identified, however all were less virulent than those already described. Virulence on Sr31 (Ug99 type of pathotypes) was not identified anywhere in India, Bangladesh, Bhutan and Nepal.
Rust surveys were undertaken in the central Highlands of Yemen during the period 20-25th May 2014. The surveys were undertaken by scientists from the Agricultural Research & Extension Authority (AREA), with the survey team being Musaed Eisa, Rashad Al Basha and Mohmmed Alsaadi. A total of 20 farmer fields were surveyed in Jahran, Qaa Alhagel, Sheraa, Rebat Alqala and Qaa Aldailamy; along with research plots at the AREA Central Highlands Research Station.
In the farmer fields the major varieties cultivated were Shaba ad Bohoth 13. Yellow rust was quite widely distributed, but in general severity was quite low. Only 6 fields recorded severity of 40-50S. Stem rust was only present in 4 fields with low incidence and severity in farmer fields. Leaf rust was absent on the surveys and no rust was observed on Barley.
On station, both yellow and stem rust were recorded at high severity (80-90S) on susceptible lines. It was noted that the stem rust infections observed were slightly unusual, as most infections normally occur in the summer season (October). Samples were collected and will be sent to the Global Rust Reference Center, Denmark for race analysis.
Extensive wheat disease surveys have been undertaken throughout the main wheat growing regions of Iran during the period February to May 2014. The surveys were coordinated by Dr Farzad Afshari, Seed and Plant Improvement Institute (SPII), Karaj and involved several institutes within Iran.
Surveys were undertaken in Khuzestan province in south-west Iran during February 2014. Surveys were conducted by Drs Afshari, Kamali, Esmaeilzadeh, Najafi Mirak and colleagues from Khuzestan. In 2013 these areas had experienced a very severe stripe rust outbreak; the current survey only recorded isolated occurrence of stripe rust in the south of the province, with no damage on farmers fields. In the north of the province (Dezful and Shosh) only 2 fields were observed with stripe and leaf rust on a susceptible cultivar. All fields visited in Shavoor and Ahvaz were free of rusts. The wheat crop was reported to be in good condition and there was seen to be no risk of either stripe or leaf rust development in this critical wheat growing state.
Surveys undertaken in the central-southern areas (Isfahan to Fars) revealed a similar picture of low disease pressure. In Isfahan, farmers fields surveyed were free of rusts. In Fars, stripe rust was detected only on susceptible cultivars such as Chamran; severity was low (20S) and given the stage of crop development there was no chance of serious rust development. In the southern parts of Fars only an estimated 1000ha of wheat were sprayed for stripe rust control in April. Countrywide it is estimated that only 6000ha have been sprayed in the current season.
In the northern areas (Mazanderan and Golestan provinces), infections of powdery mildew were observed and some patchy areas with leaf rust. Overall, there was considered to be no chance of any serious rust outbreaks developing.
During the period 17-22 May Drs Kamali and Khodarahmi surveyed Glestan, Mazanderan and Shiraz. At Gorgan research station heavy stem rust infections were observed on the cultivar Morvarid. Samples were collected for further race analysis, but a local race is suspected. No major disease problems were observed in the other areas.